A dual card dual standby terminal refers to a terminal that is provided with a dual SIM slot and that can support two subscriber identity module (SIM) cards or two universal subscriber identity module (USIM) cards to be in standby and to perform a voice or data service in two network standards. Currently, to effectively reduce power consumption, production costs, and an area of an internal chip of the dual card dual standby terminal, a radio frequency (RF) channel sharing solution, that is, two cards sharing one RF processor, is proposed, for example, a G (GSM, Global System for Mobile Communications)+G mode RF channel sharing solution or a W (WCDMA, Wideband Code Division Multiple Access)+G mode RF channel sharing solution.
A principle of a current RF channel sharing solution is: When there is a communications service on one card, a baseband communications processor of the card applies to a transceiver resource management (TRM) module for a permission to use an RF processor and notifies the TRM module of a time period for using the RF processor. If a baseband communications processor of the other card is not authorized to use the RF processor in the time period, the TRM module authorizes the baseband communications processor of the card, on which there is the communications service, to use the RF processor to perform the communications service in the time period. On the contrary, if the baseband communications processor of the other card is authorized to use the RF processor in a part or the entire of the time period, the TRM module notifies the card, on which there is a communications service, of a failure in applying for the permission to use the RF processor. That is, only when the RF processor is in an idle state, the permission to use the RF processor can be authorized to process a new communications service. It can be learned that the current RF channel sharing solution has a problem of improper allocation of a permission to use an RF processor.